Artificial tooth



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VINCENT MALLON, OF NEX YORK, N. Y., ASSIGNOR TO DENTAL MANIKTN HEAD CO.

TNC., A CORPORATION 0F NEVI YORK.

ARTIFICIAL Toorn.

meneer.

Application filed October 26,1920.

To ,all wzo/mj it may concern.'

Be it known that I, VINCENT MALLON, a citizen of the United States,residing in New York, in the county and State of New York, have inventednew and useful Improvements in Artificial Teeth, of which the followingis an exact and clear specification.

The invention relates to an artificial tooth of the type which includesa formed metallic denture or backing which is usually a casting and afacing which is usually of porcelain or similar composition, secured tothe backing by an adhesive, such as cement, and in which the connectionbetween the facing and backing includes a dovetail interlocking joint.

One of the objects of the present invention i is to provide an improvedcharacter of joint between the facing and its backing so as to.

insure the positive retention of these parts in their preset positioneven after prolonged use.

The efficiency of such jointures depends largely upon the effectivenessof the adhesion between the contacting surfaces and accordingly theinvention features an improved form of adhering surface between thefacing and its backing. This is attained largely by increasing the areaof they adhering surfaces over the area provided by a corresponding latsurface and one convenient means for attaining this increase of surfaceis to make the contacting surfaces of a curved configuration.

Still another object of the invention is to provide a tooth facing whichwill have sufcient body to maintain its configuration and give thenecessary incidental strength and at the same time which will not exposeany more of its body than is necessary to provide the facing, leavingthe metal backing to provide the necessary bulk and strength to thecompleted tooth.

ln order to attain this object the facing is formed with a thick centralor medial portion where requisite strength is desired, progressivelydecreasing in crosssectional thickness and thus thinning out to alledges which are reinforced by any desired or permissible thickness ofmetal or other strain resisting backing. I

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying draw- Specification ofLetters Patent.

Serial No. 419,591..

ings and in part will be more fully set forth in the followingparticular description of one form of mechanism embodying my invention,and the invention also consists in certain new and novel features ofconstruction and combination of parts hereinafter set forth and claimed.

ln the accompanying drawings Figure 1 is a view in front elevation of abacking constituting one of the two elements of the completed toothconstituting a preferred embodiment of the invention;

Figure 2 is an elevational view of the rear side of the facingconstituting the other element of the disclosure;

Figure 3 vis a side view of the assembled elements forming the completetooth;l

Figure 4 is a transverse sectional view taken centrally through thetooth shown in Figure 3, taken approximately on the line 4 4 of Figures1 and 2; and

Figure 5 is a horizontal sectional view taken on the line 5 5 of Figure3.

In the following description and in the claims, parts will be identifiedby specific names for convenience of expression but they are intendedto4 be as generic in their application to similar parts as the art willpermit. j

In the drawings and referring particularly to the showing in Figure 1there is disclosed a backing 10 in the form of a casting of metal, suchas gold or other material usually employed in such work. rlhe front side11 of the backing is provided with a dove-tail shaped flat` socket 12which opens through the ridge lap end 13 and is defined on oppositevertical sides by re-entrance grooves 15 which converge down wardly andinwardly to a horizontally dis-` posed stop or ledge 16 defining thelower end of the socket. The front surface 11 of the backing as well asthe back surface 17 of the socket is curved in two directions, bothvertically and horizontally when considering the tooth in normalposition. lt is equally within the scope of this disclosure to considerthe surfaces 11 and 17 as the outline of some conic section but it issimpler to consider the surfaces as having no definite geometric shapebut simply as parallel concaved surfaces.

Referring to Figure 2 for a detailed description of the facing, it is tobe understood that it is designed to conform exactly to theconfiguration of the front sides of the backing. ln order to obtain thedesired exactness of fit, the facing is used asa core in forming themold for the backing. The facing includes a body portion which is ofdouble convex form with a relatively thick central portion, particularlydesigned to strengthen the same along the vertical medial plane reducingin thickness and thus thinning out t0 all edges. r

The `upper rear portion of -tlieffacingis provided with an integralextension 18 which is clove-tailed shape in elevation and is fittedwithin the socket 17. `'.lhe lower side of the projection constitutes aledge 19 for engaging the seat 16 andcoacts therewith to preventdownward movement of the facing towards the biting edge Z0 of the tooth.

`The convexity of the front face 21 of the facing corresponds in so faras is possible to the usual curvature of the front face of a naturaltooth and of course will vary in outline with thedifferent character ofteeth which it is designed to simulate. The convexity of the rear sideof' the facing, considering both thevbody of the facing as well theprojection will be such as to conform to the correspondingly curvedfront surfaces of the backing. Following usual practice the contactinglsurfaces are cemented together by a thin layer ofk cement 22. 'Thefacing isinserted in the 'backing by moving the projecting dove-tailinto'the uppeiopen end of the socket, i. e. vfrom the gum end of thetooth and moving the facing into its prelocated position in the socketwiththe pro- `iection engaging the seat and of course with the cementlayer therebetween. TWhen so positioned the-only part of the facing ex-Y posed will be the front face, for both the distal `and mesial side ofthe tooth will be defined by the relative thick metal backingwhichextends to the outlining edge olf-"the backing, as shown in Figure3.

this construction there is provided the largest. possible adheringsurface that can be formed, takingr into consideration the necessaryspace limitations within which the entire tooth must be accommodated,taking into consideration the necessity for apportioning the facing andbacking so as togive enough strength to the facing to maintainr itsconfiguration and taking into consideration the necessity to defeatyany'tendency of the facing tocrack. By this construction it is possibleto lutilize the remaining available space to accommodate'a massofmetalbacking sufficient to vgive the` maximum amount of tensile strengthrequired of the complete tooth.

l claim 1. An artificial tooth including a formed metallic backingprovided lwith an open top, dove-tail socket in the front face thereofand an upwardly facing seat defining the lower portion of the socket,and a facing` provided with a dove-tail projection on the rear sidefitted in said socket and engaged by said seat to prevent relativemovement of the facing toward-s the bite end of the tooth, said facingadhering to the backing over a contact surface disposed in more than oneplane thereby to increase the area of the adhering surface beyond thearea of a flat cont-acting surface within the projected outlines of. thetooth. n.

2. An artificial tooth including a formed metallic backing provided withanopen top, dove-tail socket on the front face vthereof and an upwardlyfacing seat defining the lower portion ofthe-socket, .andy a facingprovided with a dove-tailprojection on the rear side 4fitted in saidsocketja-nd engaged by said seat to prevent relativeniovenient of theVfacing towards thebite end of the' tooth, said facing adhering to thebacking over a contact surface curved in one direction thereby toprovide a relatively extensive contacting area. f 1

3.4 An artificialtooth including a backing and a facing adhering tothebacking,

the' contacting surfaces between the backing and facing being curvedfromedge to edge. 4. An artificial tooth including` a backfacingbeingcurved from edge to edge in two directionsat right anglestoeach other.

An artificial tootliincluding' a. facing,

double convex in horizontal section, provid' '95 ing and afacingadheringftothe backing, the contacting surfaces between thebacking and fitting one ,side of the Ifac-ing and having'arelativelythick distal and mesial side to provide strength to the toothas a whole, saidsideshaving their forward edges terminatingapproximately at the meeting edges of said'double convex sides leavingthe front side of the facing exposedv and acting to coricealthermetallic backing. A

6. An article of manufacture constituting a facing for an artificialtooth, said facing being of one-piece`v and having a general doubleconvex form and a yprojection extending from` onefacethereof-andconstituting part of a meansv for mounting the facing inplace. l

.p VNGENT' MALLON. litnessesz y f y i B. NiooLAr, H. CRONEMEYER.

